/* ==================================================================== * Copyright (c) 2011 The OpenSSL Project. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. All advertising materials mentioning features or use of this * software must display the following acknowledgment: * "This product includes software developed by the OpenSSL Project * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" * * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to * endorse or promote products derived from this software without * prior written permission. For written permission, please contact * openssl-core@openssl.org. * * 5. Products derived from this software may not be called "OpenSSL" * nor may "OpenSSL" appear in their names without prior written * permission of the OpenSSL Project. * * 6. Redistributions of any form whatsoever must retain the following * acknowledgment: * "This product includes software developed by the OpenSSL Project * for use in the OpenSSL Toolkit (http://www.openssl.org/)" * * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED * OF THE POSSIBILITY OF SUCH DAMAGE. * ==================================================================== */ #include #include #include #include #include "../crypto/modes/internal.h" typedef struct xts128_context { void *key1, *key2; block128_f block1, block2; } XTS128_CONTEXT; static size_t CRYPTO_xts128_encrypt(const XTS128_CONTEXT *ctx, const uint8_t iv[16], const uint8_t *inp, uint8_t *out, size_t len, int enc) { union { uint64_t u[2]; uint32_t d[4]; uint8_t c[16]; } tweak, scratch; unsigned int i; if (len < 16) return 0; OPENSSL_memcpy(tweak.c, iv, 16); (*ctx->block2)(tweak.c, tweak.c, ctx->key2); if (!enc && (len % 16)) len -= 16; while (len >= 16) { #if STRICT_ALIGNMENT OPENSSL_memcpy(scratch.c, inp, 16); scratch.u[0] ^= tweak.u[0]; scratch.u[1] ^= tweak.u[1]; #else scratch.u[0] = ((uint64_t *)inp)[0] ^ tweak.u[0]; scratch.u[1] = ((uint64_t *)inp)[1] ^ tweak.u[1]; #endif (*ctx->block1)(scratch.c, scratch.c, ctx->key1); #if STRICT_ALIGNMENT scratch.u[0] ^= tweak.u[0]; scratch.u[1] ^= tweak.u[1]; OPENSSL_memcpy(out, scratch.c, 16); #else ((uint64_t *)out)[0] = scratch.u[0] ^= tweak.u[0]; ((uint64_t *)out)[1] = scratch.u[1] ^= tweak.u[1]; #endif inp += 16; out += 16; len -= 16; if (len == 0) return 1; unsigned int carry, res; res = 0x87 & (((int)tweak.d[3]) >> 31); carry = (unsigned int)(tweak.u[0] >> 63); tweak.u[0] = (tweak.u[0] << 1) ^ res; tweak.u[1] = (tweak.u[1] << 1) | carry; } if (enc) { for (i = 0; i < len; ++i) { uint8_t c = inp[i]; out[i] = scratch.c[i]; scratch.c[i] = c; } scratch.u[0] ^= tweak.u[0]; scratch.u[1] ^= tweak.u[1]; (*ctx->block1)(scratch.c, scratch.c, ctx->key1); scratch.u[0] ^= tweak.u[0]; scratch.u[1] ^= tweak.u[1]; OPENSSL_memcpy(out - 16, scratch.c, 16); } else { union { uint64_t u[2]; uint8_t c[16]; } tweak1; unsigned int carry, res; res = 0x87 & (((int)tweak.d[3]) >> 31); carry = (unsigned int)(tweak.u[0] >> 63); tweak1.u[0] = (tweak.u[0] << 1) ^ res; tweak1.u[1] = (tweak.u[1] << 1) | carry; #if STRICT_ALIGNMENT OPENSSL_memcpy(scratch.c, inp, 16); scratch.u[0] ^= tweak1.u[0]; scratch.u[1] ^= tweak1.u[1]; #else scratch.u[0] = ((uint64_t *)inp)[0] ^ tweak1.u[0]; scratch.u[1] = ((uint64_t *)inp)[1] ^ tweak1.u[1]; #endif (*ctx->block1)(scratch.c, scratch.c, ctx->key1); scratch.u[0] ^= tweak1.u[0]; scratch.u[1] ^= tweak1.u[1]; for (i = 0; i < len; ++i) { uint8_t c = inp[16 + i]; out[16 + i] = scratch.c[i]; scratch.c[i] = c; } scratch.u[0] ^= tweak.u[0]; scratch.u[1] ^= tweak.u[1]; (*ctx->block1)(scratch.c, scratch.c, ctx->key1); #if STRICT_ALIGNMENT scratch.u[0] ^= tweak.u[0]; scratch.u[1] ^= tweak.u[1]; OPENSSL_memcpy(out, scratch.c, 16); #else ((uint64_t *)out)[0] = scratch.u[0] ^ tweak.u[0]; ((uint64_t *)out)[1] = scratch.u[1] ^ tweak.u[1]; #endif } return 1; } typedef struct { union { double align; AES_KEY ks; } ks1, ks2; /* AES key schedules to use */ XTS128_CONTEXT xts; } EVP_AES_XTS_CTX; static int aes_xts_init_key(EVP_CIPHER_CTX *ctx, const uint8_t *key, const uint8_t *iv, int enc) { EVP_AES_XTS_CTX *xctx = ctx->cipher_data; if (!iv && !key) { return 1; } if (key) { /* key_len is two AES keys */ if (enc) { AES_set_encrypt_key(key, ctx->key_len * 4, &xctx->ks1.ks); xctx->xts.block1 = (block128_f) AES_encrypt; } else { AES_set_decrypt_key(key, ctx->key_len * 4, &xctx->ks1.ks); xctx->xts.block1 = (block128_f) AES_decrypt; } AES_set_encrypt_key(key + ctx->key_len / 2, ctx->key_len * 4, &xctx->ks2.ks); xctx->xts.block2 = (block128_f) AES_encrypt; xctx->xts.key1 = &xctx->ks1; } if (iv) { xctx->xts.key2 = &xctx->ks2; OPENSSL_memcpy(ctx->iv, iv, 16); } return 1; } static int aes_xts_cipher(EVP_CIPHER_CTX *ctx, uint8_t *out, const uint8_t *in, size_t len) { EVP_AES_XTS_CTX *xctx = ctx->cipher_data; if (!xctx->xts.key1 || !xctx->xts.key2 || !out || !in || len < AES_BLOCK_SIZE || !CRYPTO_xts128_encrypt(&xctx->xts, ctx->iv, in, out, len, ctx->encrypt)) { return 0; } return 1; } static int aes_xts_ctrl(EVP_CIPHER_CTX *c, int type, int arg, void *ptr) { EVP_AES_XTS_CTX *xctx = c->cipher_data; if (type == EVP_CTRL_COPY) { EVP_CIPHER_CTX *out = ptr; EVP_AES_XTS_CTX *xctx_out = out->cipher_data; if (xctx->xts.key1) { if (xctx->xts.key1 != &xctx->ks1) { return 0; } xctx_out->xts.key1 = &xctx_out->ks1; } if (xctx->xts.key2) { if (xctx->xts.key2 != &xctx->ks2) { return 0; } xctx_out->xts.key2 = &xctx_out->ks2; } return 1; } else if (type != EVP_CTRL_INIT) { return -1; } /* key1 and key2 are used as an indicator both key and IV are set */ xctx->xts.key1 = NULL; xctx->xts.key2 = NULL; return 1; } static const EVP_CIPHER aes_256_xts = { NID_aes_256_xts, 1 /* block_size */, 64 /* key_size (2 AES keys) */, 16 /* iv_len */, sizeof(EVP_AES_XTS_CTX), EVP_CIPH_XTS_MODE | EVP_CIPH_CUSTOM_IV | EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_CTRL_INIT | EVP_CIPH_CUSTOM_COPY, NULL /* app_data */, aes_xts_init_key, aes_xts_cipher, NULL /* cleanup */, aes_xts_ctrl}; const EVP_CIPHER *EVP_aes_256_xts(void) { return &aes_256_xts; }